静止から横移動を開始する船体に働く過渡的横力 : 模型実験による検討

概要

論文の詳細を見る
To calculate the magnitude of tug-power needed to execute a berthing maneuver of a VLCC, we have to estimate the lateral drag acting on the VLCC moving laterally. The lateral drag has been decided based on a constant numerical value obtained under steady flow conditions which can become visible after the VLCC ship's model has moved more than 2 or 3 lengths of the ship's model. However in the actual berthing maneuver, a ship moved only about a half length of the ship from rest. Therefore in order to estimate the lateral drag reasonably, it is necessary to obtain the informations on the lateral drag changing transitionally. In this paper, such a transitional lateral drag is investigated experimentally. Results obtained are as follows; (1) The transitional lateral drag is several times as big as the steady lateral drag, especially in the initial stag of movement. (2) The coefficients of the transitional lateral drag change dependent on the movement displacement of the ship's model. (3) The coefficients of the transitional lateral drag and the steady lateral drag were obtained experimentally for 3 kinds of load conditions of the ship's model and 4 kinds of the depth-draft ratio.
1994-03-25